Top roller for spinning machine

ABSTRACT

A TOP ROLLER FOR A SPINNING MACHINE, IN WHICH A SELFLUBRICATION OILLESS BEARING IS USED FOR BOTH A RADIAL AND THRUST ROTATIONAL SLIDING MEMBER.

June 20, 1972 NOBUKAZU MORISAKI 3,

TOP ROLLER FOR SPINNING MACHINE Filed Jan. 5, 1971 2 Sheets-Sheet 1 INVENTOR INOBUKAZU MORISAKI BY KARL /i 7 Loc K;

ATTORNEY United States Patent US. Cl. 308-20 Claims ABSTRACT OF THE DISCLOSURE A top roller for a spinning machine, in which a selflubrication oilless bearing is used for both a radial and thrust rotational sliding member.

This invention relates to a top roller for use in a spinning machine, in which self-lubricating, oilless bearings are used for both a radial and a thrust rotational sliding member and which, therefore, is operative with no lubricating oil supplied thereto.

Conventional top rollers in spinning machines have almost unexceptionally been composed of a ball-and-roller bearing having rolling members and have had many disadvantages as set forth below: Namely,

(1) The rolling members call for a lubricant, such as grease, when the top roller is used for an extended period or undergoes a fine vibration, and particularly when the load imposed thereon or the peripheral speed thereof is large.

(2) The conventional top roller requires a periodic supply of lubricant and periodic maintenance.

(3) The conventional top roller tends to be stained by the lubricant flowing thereonto and the liy waste attached thereto must be removed periodically. (The smooth rotation of the top roller tends to be impaired as a result of fly waste in air being caught on the top roller by a slight amount of lubricant leaking through an end of the bearing onto said top roller.)

(4) The construction of the bearing becomes complicated, adding to the cost of the bearing.

(5) There is a deviation between the position of the rolling members and the position where the fiber passes, and the axial contacting surface of the roller inclines about the rolling members, so that the supporting effect of a spring load is practically diminished.

(6) The absence of a lubricant, such as grease, will result in an intense wear of the roller.

(7) The periodic maintenance requires an additional labor.

Thus, it has been a strong demand in the fiber, food, paper and other industries, to eliminate such numerous disadvantages as described above. The present invention aims to overcome such disadvantages.

The construction of the top roller according to the present invention will be described with reference to the accompanying drawings, in which:

FIG. 1 is a vertical cross-sectional view showing the construction of the top roller for a spinning machine, according to the present invention; and

FIGS. 2a and 2b are diagrams showing the wear charac teristic of a bearing embodying the present invention.

Referring to FIG. 1, the top roller for use in a spinning machine, according to the present invention, comprises a hollow cylindrical roller 2, a self-lubricating oilless hollow bearing tube 3 telescoped into the axial bore 2' of said hollow cylindrical roller 2, a shaft 1 journaled in the axial bore 6 of said bearing tube 3 and having an internally threaded hole 9 in the forward end thereof, a thrust bearing disc 4 consisting of a metallic disc 4 tightened to the forward end of said shaft 1 by means of a flush bolt 5 so as to engage the forward end face 7 of said hollow bearing tube 3 and a self-lubricating oilless bearing disc 4" lined externally of said first disc 4, and a metallic end cup 8 fitted with pressure into the forward end 2" of the axial bore of said roller 2. Reference numeral 6' designates the sliding surface of the bearing tube 3 which takes a radial load. It will be obvious that the bearing disc 4" may be replaced by a self-lubricating bearing disc with a back metal (not shown), and the end cup 8 by an end plate (not shown). It will also be obvious that, instead of pro- 'viding the self-lubricating disc 4", a non-self-lubricating metallic disc (not shown) may be tightly fitted to the shaft 1 by means of the flush bolt 5 and thereafter an end cup bearing lined with a self-lubricating oilless bearing or selflubricating bearing end plate with a back metal (not shown) may be fixed in the forward end 2" of the axial bore of said roller 2 in force-fit engagement therewith. Still alternatively, a self-lubricating oilless bearing disc with a back metal thereon or a solid self-lubricating oilless bearing disc may be tightly fitted to the rearward face of the aforesaid end cup or end plate, facing the shaft, by means of a flush bolt and a non-self-lubricating metallic solid disc to the shaft by means of a flush bolt.

As stated above, it is to be understood that it is in accordance with the invention to either (a) have the oilless bearing disc fitted to the forward end face of the shaft whereby it will take a thrust given by the opposing metal end cup or end plate or,

(b) have the oilless bearing disc or bearing layer arranged on the end face of the end cup or end plate so that it will receive thrust transmitted by the metal disc fixed to the end of the shaft.

In a practical assembly it has been found to be difficult to maintain a precisely perpendicular relationship of either the metal disc or the bearing disc, or both, to the axis of the roller and accordingly there results a localized contact between the two discs.

The roller is driven to rotate together with the tightly fixed end cup (or plate) and bearing tube, while the shaft itself is maintained substantially stationary or only relatively rotatable with respect to the tube and end cup.

A bearing disc fixed on the stationary shaft, as explained in col. 1, lines 65 and 66 and col. 2, lines 1 to 12, contacts the rotating metal disc always only at the localized portion of the bearing and so a localized wearing will occur in the bearing disc thus relatively shortening the service life thereof.

On the other hand, wear of a disc-type bearing, installed in accordance with that set forth in col. 2, lines 17 to 30, wherein the bearing surface is fixed on the rotating end cup or end plate will appear over an annular surface of a bearing disc and thereby a relatively longer service life will result.

Reference numerals 7 and 7' designate, respectively, the sliding surfaces of the bearing tube 3 and the thrust bearing disc 4, which take a thrust load. The sliding surface 7 takes a thrust load acting in the leftward direction and the sliding surface 7' takes a thrust load acting in the rightward direction, as viewed in the drawing. In the illustration of FIG. 1, only one hollow bearing tube is shown as telescoped into the roller, for the purpose of showing the internal structure of the top roller, but it will be obvious that a bearing assembly comprising a plurality of bearing tubes may be provided within the roller depending upon the size of the roller and the size of the load imposed thereon.

Now, a practical example of the present invention will be illustrated hereunder: A hollow cylindrical self-lubricating oilless solid bearing tube 3 which had an outer diameter of 15 mm., an inner diameter of 9.1 mm. and an axial length of 15 mm. and had been produced by compression-molding a mixture consisting of 60% by weight of powdered polytetra-fluoroethylene, 20% by weight of powdered bronze and 20% by weight of powdered graphite, and sintering the resultant molding at a temperature of 360-370 C.; a two-layer bearing disc 4 which consisted of a disc 4 made from Japanese Industrial Standards S 3308 carbon steel band steel (strip (SPMB)) and having a thickness of 2.5 mm. and a diameter of 14 mm., and a bearing layer 4" of a porous sintered bronze layer impregnated with a mixture of polytetra-fiuoroethylene and lead and disposed on the exterior face of said disc 4 (such as the disc disclosed in Japanese patent publication No. 16,950/ .64); a metallic end cup 8 made from Japanese Industrial Standards G 3101 material (rolled structural steel (S841) .for use in common structures); a shaft 1 made of Japanese Industrial Standards G 4051 carbon steel S 400 for mechanical structure parts; and a brass screw with a cross recessed flush head (phillips screw were assembled in the manner shown in FIG. 1 and the resultant top roller was incorporated in a practically use spinning machine to test the wear characteristic of the bearing under the following conditions:

, (l) A load w of 10 kg. was imposed on the shaft 1 (5 kg. of load on each end of the shaft).

(2) The roller 2 was driven at the rate N of 10 rpm.

(3) The surface roughness of the shaft 1 was 1.5 S(W) Under such conditions, the bearing surface pressure P is represented by the following formula:

d the inner diameter of the bearing tube which is 9.1 mm. 1: the axial length of the bearing tube which is mm.

The peripheral speed V (m./min.) of the roller is represented by the formula;

1r dXN During the test conducted under the above conditions,

a change in the inner diameter of the bearing tube 3 with the passage of time (i.e. the rate of wear) was measured and the measured values were plotted to obtain wear characteristic curves of FIGS. 2(a) and 2(b). As will be apparent from FIG. 2(a), the amount of change in inner diameter of the bearing is about 1011. after about 1,000

hours of testing. Further, as will be seen from FIG. 2(b),

no substantial change in the rate of wear could be observed when fly waste was intentionally attached within or to one end of the bearing. It was also found that the amount of wear of the shaft 1 was almost zero. The wear characteristic curves A (Sample No. l) and B (Sample No. 2)

in FIG. 2(a) represent the self-lubricating oilless solid bearing tube 3 force-fitted in the left hand side roller (the one of which the internal structure is shown) of the arrangement illustrated in FIG. 1 and the one force-fitted in the right hand side roller (of which the internal struc ture is not shown) of the same respectively. These wear characteristic curves were obtained under the condition in which no fly waste was present in or at the end of the bearing. The wear characteristic curves C (Sample No. 1)

and D (Sample No. 2) shown in FIG. 2(b) represent the self-lubricating oilless solid bearing tube 3 force-fitted in the left hand side roller (the one of which the internal structure is shown) of the arrangement of FIG. 1 and the one force-fitted in the right hand side roller (of which the internal structure is not shown) of the same respectively. These wear characteristic curves were obtained under the condition in which fly waste was intentionally attached within or to the end of the bearing. In the light of the wear characteristic curves of FIG. 2 and the state of generation of powder due to friction it is considered that the top roller according to the present invention does not follow the process of initial running-in to constant wear, but the wear and time proceed in the relation of linear expression. The top roller of the invention is expected to be useful for at least 5 years when calculated reversely from the tolerable value of clearance. The amount of wear of the sliding surface 7', of the thrust bearing disc 4 was not measured because it is negligibly small in practice.

Since the top roller of the invention is constructed as described above and completely self-lubricating, there is no necessity of lubrication. Therefore, it operates stably at a low speed, with a low load and with a minimum wear, with no fear of dust being attached thereto as a result of it being stained with oil. In addition, it has a long service life, can be maintained, produced and assembled easily, and is free of an electrostatic trouble caused by friction. The present invention will bring about remarkable advantages when applied to a bearing which takes both a radial and thrust loads.

What is claimed is:

1. For use in a spinning machine, a top roller incorporating self-lubricating oilless bearings to take a radial force and thrust, comprising:

a hollow cylindrical roller; a hollow cylindrical oilless bearing tube press-fitted in the axial bore of said roller; a shaft relatively rotatably received in said tube; a metal backed composite oilless bearing disc member fitted to the end face of said shaft and having a sintered oilless bearing layer positioned spaced from said bearing tube and having an unsintered face of the backing metal in contact with the end face of said bearing tube, said end face being perpendicular to the axis of said roller; and an end cup or end plate press-fitted into the end portion of the axial bore of said roller whereby said tube and end cup or end plate take both radial force and thrust on said shaft through said bearing disc.

2. A top roller as claimed in claim 1 wherein the oilless bearing disc member is composed of a solid oilless bearing disc and a solid metal disc and both discs are fitted integrally to the end face of said shaft with its metal plate in contact with the end face of said bearing tube perpendicular to the axis of said roller.

3. For use in a spinning machine, a top roller incorporating self-lubricating oilless bearings to take a radial force and thrust, comprising:

a hollow cylindrical roller, a hollow cylindrical oilless bearing tube press-fitted in the axial bore of said roller; a shaft relatively rotatably received in said tube; a metal disc fitted to the end face of said shaft perpendicular to the axis of said roller; an end cup or end plate press-fitted into the end portion of the axial bore of said roller and a composite oilless bearing disc member with a back metal fitted to the end face of said end cup or end plate so that the oilless bearing layer of said composite bearing disc member sintered on the backing metal may be positioned to facing with the free side end of said metal disc fitted to said shaft.

4. A top roller as claimed in claim 3 wherein a solid oilless bearing disc is fitted to said end cup or end plate at the end face thereof facing with the free end of said metal disc fitted to said shaft.

5. A top roller as claimed in claim 3 wherein said end cup or end plate has an oilless bearing layer sintered on the end face thereof facing with the free end of said 2,766,076 10/1956 Saxe 3082O metal disc fitted to said shaft. 2,775,793 1/1957 Cotchett 308-238 3,583,778 6/1971 Mori 308-240 References Cited UNITED STATES PATENTS 5 MARTIN P. SCHWADRON, Primary Examiner 2 4 3 345 9 1949 Lee 30 20 B. GROSSMAN, Assistant Examiner 2,995,462 8/1961 Mitchell et a1 308238 2,253,141 8/1941 Schofield 30s-20 2,601,371 6/1952 Cotchett et a1 3os -23s 308-238 

